Method for managing document on basis of blockchain by using UTXO-based protocol, and document management server using same

ABSTRACT

The present invention relates to a method for managing a document on the basis of a blockchain by using an unspent transaction output (UTXO)-based protocol, and a server using the same. Specifically, the purpose of the present invention is to manage a document, and the present invention relates to: a method for preparing a document, that is, a method for issuing a document; a method for using the prepared document, that is, a method for reading the prepared document; and a method for handling the prepared document, particularly, a method for destroying the prepared document.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a bypass continuation of PCT/KR2018/004455, filedApr. 17, 2018, which claims foreign priority to Korean application10-2017-0048993 filed Apr. 17, 2017, the disclosures of each areincorporated herein by reference in their entireties.

FIELD OF THE DISCLOSURE

The present disclosure relates to a method for managing a document basedon a blockchain by using a UTXO (unspent transaction output) basedprotocol and a server using same, and more particularly, in order tomanage the document, to the method for generating, i.e., issuing, thedocument, the method for using, i.e., viewing, the generated document,and the method for handling the generated document, especially, forrevoking the document.

That is, the present disclosure relates to the issuing method, theviewing method, and the revoking method for managing the document, andthese methods correspond to the method for generating the document, themethod for using the document, and the method for handling the document,and will be regarded as a group of inventions having technicalinter-connectivity.

BACKGROUND OF THE DISCLOSURE

The governments around the world, as well as the government of theRepublic of Korea, and related organizations put a lot of resources andeffort into the processing of numerous documents. Documents handled bylarge organizations, such as governments, sometimes require high levelsof confidentiality and security, and sometimes require accuracy, speed,and openness. Meanwhile, in line with the worldwide computerizationtrend, the documents are distributed in the form of electronic documentsthat are lighter and more favorable for reproduction and storage.

However, the electronic documents are exposed to external hacking orinternal manipulation. The original document may be forged or falsifiedby public officials without any permission, and the person handling thedocument may deny the actual content of the document because of theforgery. It can also be a problem that an unauthorized person falsifiesan authority and make a false document.

SUMMARY OF THE DISCLOSURE

It is an object of the present disclosure to solve all theaforementioned problems.

It is another object of the present disclosure to store information onidentity authentication and electronic document issuance in ablockchain, to thereby minimize risk of an unauthorized person forging adocument.

It is still another object of the present disclosure to provide afunction of strong non-repudiation, by confirming that the document isgenerated by an authorized person and distributed without tampering oncethe document is issued.

It is still yet another object of the present disclosure to periodicallyverify an authenticity of an electronic document, to thereby guaranteethat the electronic document is not forged or falsified.

It is still yet another object of the present disclosure to guaranteesecurity and prevent forgery, by forcing every entity participating inissuing, viewing and revoking of the electronic document to usecryptographical technology like a public key-private key pair algorithm,e.g., RSA, ECC, and hash functions, etc.

In order to accomplish objects above, representative structures of thepresent disclosure are described as follows.

In accordance with one aspect of the present disclosure, there isprovided a method for issuing a document based on a blockchain,including steps of: (a) a document-managing server, if adocument-issuing request from a document issuance requester is acquired,instructing a document-issuing server of a document-issuing institutionwhich has an issuance permission of the document to acquireidentification information on the document wherein a managementpermission of the document is given to the document-issuing institution,and instructing a document-storing device to acquire locationinformation representing where the document is generated or stored byreferring to the identification information on the document, to therebyacquire information on an original document including the documentitself or its processed one which is generated or stored ascorresponding to the location information; and (b) (i) thedocument-managing server generating contents of a document-transmittingtransaction representing a transfer of the management permission of thedocument from the document-issuing institution as a transmitter of thedocument to the document issuance requester as a recipient of thedocument, and transmitting the document-transmitting transaction to ablockchain database, to thereby instruct the blockchain database tostore a document-transmitting transaction function value, created byapplying a specific operation to the document-transmitting transaction,in the blockchain database itself, and (ii) the document-managing serverdisplaying or supporting another device connected with thedocument-managing server to display access information, to be used foraccessing an issuance result of the document and the information on theoriginal document, to the document issuance requester.

As one example, the step of (b) further includes a process of: (iii) thedocument-managing server transmitting the information on the originaldocument to the blockchain database or another database connected withthe document-managing server, to thereby allow the blockchain databaseor said another database to retain the information on the originaldocument.

As one example, at the process of (ii) in the step of (b), the accessinformation is retrieved from the blockchain database. 4. The method ofclaim 1, wherein the document-transmitting transaction includes headerinformation, a transaction input, a transaction output, and at least oneredeeming condition-determining code configured to determine at leastone redeeming condition.

As one example, the header information includes transaction versioninformation, transaction type information, and a time-stampcorresponding to a time of occurrence of the document-transmittingtransaction.

As one example, the transaction input includes at least one of (i)information on personnel with a document-viewing permission representingwho has the document-viewing permission of the document, (ii) a previousdocument-transmitting transaction function value created by applying thespecific operation to each previous document-transmitting transactionwhich is referred to by the document-transmitting transaction, (iii) anoutput index of said each previous document-transmitting transaction,and (iv) at least one signature value of at least one documenttransmitter who transmitted the document.

As one example, the transaction input further includes documentinformation, and wherein the document information includes an issuancetime and date of the document, a type of the document, a title of thedocument, a document-information function value created by applying thespecific operation to the information on the original document,information on the document issuance requester who requested thedocument, a unique identifier of the document, information on thedocument-issuing institution, information on a document-issuing personin charge of issuing the document, information on authenticity of thedocument, and the access information on the document.

As one example, the information on the document issuance requesterincludes a name of the document issuance requester and an identifier ofthe document issuance requester, and wherein the identifier of thedocument issuance requester is a universally unique identifier (UUID).

As one example, the transaction input further includes at least onepiece of additional document information, and wherein the additionaldocument information includes (i) a transaction ID representinginformation on a location of the document-transmitting transactionfunction value, created by applying the specific operation to thedocument-transmitting transaction, in the blockchain database, (ii) acontent section, and (iii) a signature section.

As one example, the content section includes a public key of an authorof the additional document information, a time-stamp corresponding to atime of creation of the additional document information, and a commentadded by the author of the additional document information, and whereinthe signature section includes a signature value created by signing thecontent section with a private key of the author of the additionaldocument information.

As one example, the previous document-transmitting transaction functionvalue included in the document-transmitting transaction corresponding toan issuance of the document is a null function value, and wherein thesignature value of said at least one document transmitter is a signaturevalue of the document-issuing institution, and wherein the signaturevalue of said at least one document transmitter is included in thedocument-transmitting transaction.

As one example, the redeeming condition-determining code is a smartcontract, wherein the smart contract is (i) a source code which iscompiled into bytecodes capable of an execution on at least onecomputing device, (ii) configured to perform management of the documentaccording to whether the redeeming condition is satisfied, at a time ofthe execution, and wherein an integrity resulting from the execution isverified by a consensus outputted from the computing device.

As one example, the redeeming condition is at least one of one or moredocument-transmitting and document-viewing conditions, one or moredocument restriction conditions, and a document fee-charging condition.

As one example, the document-transmitting and document-viewingconditions include at least one of (i) a condition for allowing thedocument to be viewed by at least one person, (ii) a condition forallowing transmission of the document to a third party, (iii) acondition for requiring a document-viewing person to log a fact that thedocument-viewing person viewed the document, (iv) a condition forrequiring the document-viewing person to log a fact that thedocument-viewing person confirmed a content of the document, (v) acondition for restricting the document to be viewed by at least onepredetermined specific entity only, (vi) a condition for restricting thedocument to be viewed by one or more entities belonging to apredetermined specific party only, (vii) a condition for preventing atleast one predetermined certain entity from viewing the document, (viii)a condition for restricting the document to be viewed only if at leastone predetermined particular entity allowed the document to be viewed,and (ix) a condition for restricting the number of the transmission ofthe document to be less than a predetermined number.

As one example, the document restriction conditions include at least oneof (i) a condition for preventing the information on the originaldocument from being printed, and (ii) a condition for allowingtransmission of the information on the original document via e-mails.

As one example, the document fee-charging condition is for charging afee on at least one of an issuance, a view, and a revocation of thedocument.

As one example, the transaction output includes an address of at leastone document recipient, a name of the document recipient, and anidentifier of the document recipient.

In accordance with another aspect of the present disclosure, there isprovided a method for viewing a document based on a blockchain,including steps of: (a) a document-managing server, on condition thatinformation on an original document including the document itself or itsprocessed one of the document has been issued in response to adocument-issuing request from a document issuance requester, and adocument-transmitting transaction function value created by applying aspecific operation to one or more document-transmitting transactions hasbeen stored in a blockchain database wherein the document-transmittingtransactions have either (i) a document-issuing institution as atransmitter of the document and the document issuance requester as alast recipient of the document thus far, or (ii) a first specificrecipient as the transmitter of the document and a second specificrecipient as the last recipient of the document thus far, if adocument-viewing request including access information for accessing thedocument is acquired from a document-viewing requester, determiningwhether a document-viewing permission for the document is granted to thedocument-viewing requester; and (b) the document-managing server, if thedocument-viewing permission is determined as granted to thedocument-viewing requester, (i) transmitting the access information foraccessing the document to the blockchain database or another database,to thereby instruct the blockchain database or said another database toprovide the information on the original document, corresponding to theaccess information, to the document-managing server or to another deviceconnected with the document-managing server, and if the information onthe original document is acquired, displaying or supporting anotherdevice to display the information on the original document to thedocument-viewing requester.

As one example, whether the document-viewing permission is granted tothe document-viewing requester is determined by referring to at leastone of (i) a document-transmitting and document-viewing condition of aredeeming condition-determining code included in a lastdocument-transmitting transaction among the document-transmittingtransactions, and (ii) information on personnel with thedocument-viewing permission in a transaction input included in the lastdocument-transmitting transaction.

As one example, if a document-viewing request, including the accessinformation, for the document is acquired from the document-viewingrequester who is different from the last recipient of the document thusfar at the step of (a), then the step of (b) further includes a processof (ii) generating a content of an additional document-transmittingtransaction which is a document-transmitting transaction that transfersa management permission of the document with the last recipient of thedocument thus far as the transmitter of the document and with thedocument-viewing requester as the recipient of the document, andtransmitting the access information and the additionaldocument-transmitting transaction to the blockchain database, to therebyallow the blockchain database to provide the information on the originaldocument, corresponding to the access information, to thedocument-managing server, and to store the additionaldocument-transmitting transaction in the blockchain database itself.

As one example, the transaction input of the additionaldocument-transmitting transaction includes a value created by applyingthe specific operation to a last document-transmitting transaction as aprevious document-transmitting transaction function value.

As one example, at the process of (ii) in the step of (b), if anadditional input from the document-viewing requester is acquired, thedocument-managing server incorporates additional document informationinto the additional document-transmitting transaction, such that acontent section of the additional document information includes theadditional input.

In accordance with still another aspect of the present disclosure, thereis provided a method for revoking a document which is managed using ablockchain, including steps of: (a) a document-managing server, oncondition that information on an original document including thedocument itself or its processed one of the document has been issued inresponse to a document-issuing request from a document issuancerequester, and a document-transmitting transaction function valuecreated by applying a specific operation to one or moredocument-transmitting transactions has been stored in a blockchaindatabase wherein the document-transmitting transactions have either (i)a document-issuing institution as a transmitter of the document and thedocument issuance requester as a last recipient of the document thusfar, or (ii) a first specific recipient as the transmitter of thedocument and a second specific recipient as the last recipient of thedocument thus far, if a document-revoking request including accessinformation for accessing the document is acquired from a documentrevocation requester, determining whether a document-revoking permissionfor the document is granted to the document revocation requester; and(b) the document-managing server, if the revocation permission isdetermined as granted to the document revocation requester, transmittinga document-revoking transaction which is a document-transmittingtransaction for transferring a management permission of the document tothe blockchain database with the last recipient of the document thus faras the transmitter of the document and with an address for revocation asan address of the recipient of the document, to thereby allow theblockchain database to store a document-revocation function valuecreated by applying the specific operation to the document-revokingtransaction in the blockchain.

As one example, a private key corresponding to the address forrevocation is stored by a managing entity.

In accordance with still yet another aspect of the present disclosure,there is provided a document-managing server for issuing a documentbased on a blockchain, including: a communication part for acquiring adocument-issuing request from a document issuance requester; and aprocessor configured to execute instructions to perform or supportanother device to perform processes of: (I) instructing adocument-issuing server of a document-issuing institution which has anissuance permission of the document to acquire identificationinformation on the document wherein a management permission of thedocument is given to the document-issuing institution, and instructing adocument-storing device to acquire location information representingwhere the document is generated or stored by referring to theidentification information on the document, to thereby acquireinformation on an original document including the document itself or itsprocessed one which is generated or stored as corresponding to thelocation information and (II) (i) generating contents of adocument-transmitting transaction representing a transfer of themanagement permission of the document from the document-issuinginstitution as a transmitter of the document to the document issuancerequester as a recipient of the document, and transmitting thedocument-transmitting transaction to a blockchain database, to therebyinstruct the blockchain database to store a document-transmittingtransaction function value, created by applying a specific operation tothe document-transmitting transaction, in the blockchain databaseitself, and (ii) displaying or supporting another device connected withthe document-managing server to display access information, to be usedfor accessing an issuance result of the document and the information onthe original document, to the document issuance requester.

As one example, the process of (II) further includes a process of: (iii)transmitting the information on the original document to the blockchaindatabase or another database connected with the document-managingserver, to thereby allow the blockchain database or said anotherdatabase to retain the information on the original document.

As one example, at the process of (ii), the access information isretrieved from the blockchain database.

In accordance with still yet another aspect of the present disclosure,there is provided a document-managing server for viewing a documentbased on a blockchain, including: a communication part for, on conditionthat information on an original document including the document itselfor its processed one of the document has been issued in response to adocument-issuing request from a document issuance requester, and adocument-transmitting transaction function value created by applying aspecific operation to one or more document-transmitting transactions hasbeen stored in a blockchain database wherein the document-transmittingtransactions have either (i) a document-issuing institution as atransmitter of the document and the document issuance requester as alast recipient of the document thus far, or (ii) a first specificrecipient as the transmitter of the document and a second specificrecipient as the last recipient of the document thus far, acquiring adocument-viewing request including access information for accessing thedocument from a document-viewing requester; and a processor fordetermining whether a document-viewing permission for the document isgranted to the document document-viewing requester; wherein, if thedocument-viewing permission is determined as granted to the documentdocument-viewing requester, the processor performs processes of (i)transmitting the access information for accessing the document to theblockchain database or another database, to thereby instruct theblockchain database or said another database to provide the informationon the original document, corresponding to the access information, tothe document-managing server or to another device connected with thedocument-managing server, and if the information on the originaldocument is acquired, displaying or supporting another device to displaythe information on the original document to the document-viewingrequester.

As one example, if a document-viewing request, including the accessinformation, for the document is acquired from the document-viewingrequester who is different from the last recipient of the document thusfar, then the process further performs a process of (ii) generating acontent of an additional document-transmitting transaction which is adocument-transmitting transaction that transfers a management permissionof the document with the last recipient of the document thus far as thetransmitter of the document and with the document-viewing requester asthe recipient of the document, and transmitting the access informationand the additional document-transmitting transaction to the blockchaindatabase, to thereby allow the blockchain database to provide theinformation on the original document, corresponding to the accessinformation, to the document-managing server, and to store theadditional document-transmitting transaction in the blockchain databaseitself.

As one example, at the process of (ii), if an additional input from thedocument-viewing requester is acquired, the processor incorporatesadditional document information into the additionaldocument-transmitting transaction, such that a content section of theadditional document information includes the additional input.

In accordance with still yet another aspect of the present disclosure,there is provided a document-managing server for revoking a documentwhich is managed using a blockchain, including: a communication partfor, on condition that information on an original document including thedocument itself or its processed one of the document has been issued inresponse to a document-issuing request from a document issuancerequester, and a document-transmitting transaction function valuecreated by applying a specific operation to one or moredocument-transmitting transactions has been stored in a blockchaindatabase wherein the document-transmitting transactions have either (i)a document-issuing institution as a transmitter of the document and thedocument issuance requester as a last recipient of the document thusfar, or (ii) a first specific recipient as the transmitter of thedocument and a second specific recipient as the last recipient of thedocument thus far, acquiring a document-revoking request includingaccess information for accessing the document from a document revocationrequester; and a processor for determining whether a document-revokingpermission for the document is granted to the document revocationrequester; wherein, if the revocation permission is determined asgranted to the document revocation requester, the processor performs aprocess of transmitting a document-revoking transaction which is adocument-transmitting transaction for transferring a managementpermission of the document to the blockchain database with the lastrecipient of the document thus far as the transmitter of the documentand with an address for revocation as an address of the recipient of thedocument, to thereby allow the blockchain database to store adocument-revocation function value created by applying the specificoperation to the document-revoking transaction in the blockchain.

Further, in accordance with still yet another example embodiments of thepresent disclosure, a document-managing server for performing methodsmentioned above is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings to be used to explain example embodiments of thepresent disclosure are only part of example embodiments of the presentdisclosure and other drawings can be obtained based on the drawings bythose skilled in the art of the present disclosure without inventivework.

FIG. 1 is a conceptual diagram illustrating a document-managing serverfor performing a method for managing a document in accordance with afirst example embodiment and a second example embodiment of the presentdisclosure.

FIG. 2 is a conceptual diagram exemplarily illustrating a configurationof an entire system, including the document-managing server, adocument-issuing server, a document-storing device, and a blockchaindatabase, as a system for performing the method for managing thedocument in accordance with the first example embodiment and the secondexample embodiment of the present disclosure.

FIG. 3 is a sequence diagram schematically illustrating a method forissuing and viewing the document in accordance with the presentdisclosure.

FIG. 4 is a sequence diagram schematically illustrating another exampleembodiment wherein a document issuance requester provides accessinformation, for accessing the issued document, to a document-viewingrequester of the method for issuing and viewing the document inaccordance with the present disclosure.

FIG. 5 is a conceptual diagram schematically illustrating aconfiguration of a document-transmitting transaction in accordance withthe present disclosure.

FIG. 6 is a conceptual diagram schematically illustrating aconfiguration of the document-transmitting transaction generated at atime of issuing the document in accordance with the present disclosure.

FIGS. 7A to 7C are conceptual diagrams for comparing a configuration ofan additional document-transmitting transaction which is thedocument-transmitting transaction created at a time of transmitting thedocument, a configuration of the document-transmitting transactioncreated at the time of issuing the document, and a configuration of thedocument-transmitting transaction created at a time of revoking thedocument.

FIGS. 8A to 8C are conceptual diagrams for comparing a configuration ofthe document-transmitting transaction in which the document istransferred to a single document recipient by agreement of multipledocument transmitters, a configuration of the document-transmittingtransaction in which the document is transferred to multiple documentrecipients from a single document transmitter, and a configuration ofthe document-transmitting transaction in which the document istransferred to the multiple document recipients from the multipledocument transmitters.

FIG. 9 is a drawing schematically illustrating a process of viewinghistory of entire document-transmitting transactions.

FIGS. 10 and 11 are drawings schematically illustrating a process ofrecording the document-transmitting transaction in a blockchain inaccordance with the second example embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Detailed explanation on the present disclosure to be made below refer toattached drawings and diagrams illustrated as specific embodimentexamples under which the present disclosure may be implemented to makeclear of purposes, technical solutions, and advantages of the presentdisclosure. These embodiments are described in sufficient detail toenable those skilled in the art to practice the present disclosure.

Throughout the present specification, a “database” may be systematicdata, i.e., integral sets of managed information and its managementsystem, and may include a general relational database, MongoDB, and ablockchain database, but the scope of the present disclosure is notlimited thereto. The present specification describes a blockchaindatabase of a virtual currency for convenience of explanation, but thoseskilled in the art understand that the scope of the present disclosureis not limited thereto.

Throughout the present specification, a “public blockchain” may be ablockchain used publicly, and may be accessible by a document-managingserver in accordance with the present disclosure.

The blockchain may be used for the virtual currency, and the virtualcurrency may be digital currency distributed by transactions based ondigital wallets of blockchain technology, such as Bitcoin, Litecoin,Darkcoin, Namecoin, Dogecoin, Ripple, etc.

Further, in this specification, a “private blockchain” indicates anindependently configured private blockchain, that is, the blockchainmanaged directly by the servers in accordance with the presentdisclosure, not the public blockchain.

Also, throughout the present specification, a “blockchain” may representa public blockchain and a private blockchain.

Besides, in the detailed description and claims of the presentdisclosure, a term “include” and its variations are not intended toexclude other technical features, additions, components or steps. Otherobjects, benefits and features of the present disclosure will berevealed to those skilled in the art, partially from the specificationand partially from the implementation of the present disclosure. Thefollowing examples and drawings will be provided as examples but theyare not intended to limit the present disclosure.

Moreover, the present disclosure covers all possible combinations ofexample embodiments indicated in this specification. It is to beunderstood that the various embodiments of the present disclosure,although different, are not necessarily mutually exclusive. For example,a particular feature, structure, or characteristic described herein inconnection with one embodiment may be implemented within otherembodiments without departing from the spirit and scope of the presentdisclosure. In addition, it is to be understood that the position orarrangement of individual elements within each disclosed embodiment maybe modified without departing from the spirit and scope of the presentdisclosure. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope of the present disclosure isdefined only by the appended claims, appropriately interpreted, alongwith the full range of equivalents to which the claims are entitled. Inthe drawings, like numerals refer to the same or similar functionalitythroughout the several views.

In a first example embodiment of the present disclosure, a document isissued, a user is allowed to transmit and view the document, and thedocument is allowed to be revoked as need be, and transactions regardingissuance, transmission, view, and revocation as such are recorded in afirst blockchain, for document management based on the blockchain inaccordance with the present disclosure.

In a second example embodiment of the present disclosure, thetransactions regarding the issuance, the transmission, the view, and therevocation are stored in the first blockchain, and a representativefunction value, e.g., a representative hash value generated from thetransactions stored in the first blockchain, is stored in a secondblockchain. That is, the second example embodiment is configured in atype of an anchoring method which improves an integrity of storedinformation in double.

For reference, in accordance with the present disclosure, the firstblockchain may be a database where data is stored directly, and thesecond blockchain may be a database where the data is stored indirectlyvia the first blockchain for ensuring the integrity of the data.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentand context clearly dictates otherwise. These embodiments will bedescribed in sufficient detail by referring to attached drawingsregarding the embodiments of the present disclosure to allow thoseskilled in the art to practice the disclosure.

FIG. 1 is a drawing schematically illustrating a document-managingserver for providing a document management service in accordance withone example embodiment of the present disclosure.

By referring to FIG. 1, the document-managing server in accordance withthe present disclosure, may be a computing device 100 including acommunication part 110 and a processor 120 and may communicate directlyor indirectly with other computing devices. The document-managing servermay be comprised of multiple computing devices, and a document-issuingserver and the blockchain database may also be comprised of multiplecomputing devices.

Specifically, servers such as the document-managing server, thedocument-issuing server, the blockchain database, etc. and a user deviceprovided for the document management in accordance with the presentdisclosure may typically achieve a desired system performance by usingcombinations of at least one computing device and at least one computersoftware, e.g., a computer processor, a memory, a storage, an inputdevice, an output device, or any other conventional computingcomponents, an electronic communication device such as a router or aswitch, an electronic information storage system such as anetwork-attached storage (NAS) device and a storage area network (SAN)as the computing device and any instructions that allow the computingdevice to function in a specific way as the computer software.

The communication part 110 of such computing devices may transmitrequests and receive responses with other connected devices. As oneexample, such requests and responses may be carried out by the same TCPsession, but they are not limited to these. For example, they could betransmitted and received as UDP datagrams.

Also, the processor 120 of such devices may include hardwareconfiguration of MPU (Micro Processing Unit) or CPU (Central ProcessingUnit), cache memory, data bus, etc. Additionally, any OS and softwareconfiguration of applications that achieve specific purposes may befurther included.

Next, FIG. 2 is a conceptual diagram exemplarily illustrating aconfiguration of an entire system, including the document-managingserver 210, the user device 220, the document-issuingserver/document-storing device 230, and the blockchain database 240, asa system for performing the method for managing documents in accordancewith the present disclosure. FIG. 2 is just an example, and thedocument-managing server 210 may be a single computing device, or mayalso be comprised of the multiple computing devices which may bestand-alone or connected with each other cooperatively.

As will be described later, the document management method in accordancewith the present disclosure includes steps as follows: {circle around(1)} in response to the document-issuing request from the user device,{circle around (2)} information on an original document which includesthe document itself or its processed one is acquired, {circle around(3)} a transaction regarding the document is recorded in the blockchain,and {circle around (4)} access information for using the information onthe original document is displayed to the document issuance requestervia the user device 220. Herein, the indicated numbers of the steps of{circle around (3)} the recordation in the blockchain and {circle around(4)} the display of the access information are arbitrary, and thoseskilled in the art well understand that the steps {circle around (3)}and {circle around (4)} may be performed simultaneously, or the step{circle around (3)} may be performed after the step {circle around (4)}.

Thereafter, {circle around (5)} the access information may be providedfrom the document issuance requester to a document-viewing requester whois different from the document issuance requester, and {circle around(6)} the document-viewing requester may request viewing of theinformation on the original document using the access information. Then,since the document is transmitted from the document issuance requesterto the document-viewing requester, {circle around (7)} thedocument-transmitting transaction corresponding to the document isrecorded in the blockchain, and {circle around (8)} the document-viewingrequester may view the document using the information on the originaldocument.

Details of whole processes as such will be explained as below.

First Example Embodiment

A method for issuing the document based on the blockchain in accordancewith the first example embodiment of the present disclosure is describedas follows.

FIG. 3 is a sequence diagram schematically illustrating the method forissuing and viewing the document in accordance with the presentdisclosure.

By referring to FIG. 3, in the method for issuing the document inaccordance with the first example embodiment of the present disclosure,first, the document-managing server may acquire the document-issuingrequest of the document issuance requester at a step of S305. If thedocument-issuing request from the document issuance requester isacquired, the document-managing server may perform processes ofinstructing the document-issuing server, of a document-issuinginstitution which has an issuance permission of the document, to acquireidentification information on the document where a management permissionof the document is given to the document-issuing institution, andinstructing the document-storing device to acquire location informationrepresenting where the document is generated or stored, by referring tothe identification information on the document at a step of S310.Throughout the present specification, the location information mayrepresent where the document is generated or stored by thedocument-storing device or by other storage devices. As a result, thedocument-managing server may acquire the information on the originaldocument including the document itself or its processed one at a step ofS315. Specifically, the information on the original document may includethe document itself or information on a state of the processed document,which is generated or stored as corresponding to the locationinformation.

Next, after the steps of S305 to S315, the method for issuing thedocument may further include steps as follows: the document-managingserver generates contents of a document-transmitting transactionrepresenting a transfer of the management permission of the documentfrom the document-issuing institution as a transmitter of the documentto the document issuance requester as a recipient of the document at astep of S320, and transmits the document-transmitting transaction to theblockchain database, to thereby instruct the blockchain database tostore a document-transmitting transaction function value, created byapplying a specific operation to the document-transmitting transaction,in the blockchain database itself at a step of S330. Thedocument-transmitting transaction is disclosed in detail later byreferring to drawings. Throughout the present disclosure, a specificfunction or a specific operation may be a hash function, a functionvalue may be a hash value generated by using the hash function, aspecific tree may be a Merkle tree or a Patricia tree, and arepresentative function value of the specific tree may be a root valueof the Merkle tree, but the scope of the present disclosure is notlimited thereto.

For reference, hash functions used in the present disclosure may includeat least one of an MD4 function, an MD5 function, an SHA-0 function, anSHA-1 function, an SHA-224 function, an SHA-256 function, an SHA-384function, an SHA-512 function, an HAS-160 function, and a Triple SHA256function, but those skilled in the art understand that the scope of thepresent disclosure is not limited thereto.

Also, after the steps of S305 to S330, the method for issuing thedocument in accordance with the first example embodiment of the presentdisclosure may further include steps as follows: the document-managingserver displays or supports another device connected with thedocument-managing server to display the access information, to be usedfor accessing an issuance result of the document and the information onthe original document, to the document issuance requester at steps ofS335 and S340. Herein, the access information may be, for example, a URLlink provided for viewing the information on the original document, andmay be retrieved from the blockchain database.

The aforementioned processes of S320 and S330 may be performedsimultaneously or non-simultaneously with the processes of S335 andS340, and if the processes are performed non-simultaneously, theirprocessing order may be arbitrary.

Meanwhile, the method for issuing the document in accordance with thefirst example embodiment of the present disclosure may further include aprocess (not illustrated) in addition to the aforementioned processes ofS320, S330, S335, and S340 as follows: the document-managing servertransmits the information on the original document to the blockchaindatabase or another database connected with the document-managingserver, to thereby allow the blockchain database or said anotherdatabase to retain the information on the original document.

Herein, since the information on the original document is generated orstored by the document-issuing server as corresponding to the locationinformation, the information on the original document may not have to beretained separately. However, as the case may be, the information on theoriginal document may be retained separately.

FIG. 5 is a conceptual diagram schematically illustrating aconfiguration of the document-transmitting transaction in accordancewith the present disclosure.

By referring to FIG. 5, the document-transmitting transaction 500 mayinclude header information 510, a transaction input 520, a transactionoutput 530, and at least one redeeming condition-determining code 540configured to determine at least one redeeming condition. FIG. 5 showsthe redeeming condition-determining code as a smart contract, however,this is just an example, and the redeeming condition-determining codewill be explained in more detail as follows.

Herein, the header information 510 may include transaction versioninformation, transaction type information, and a time-stampcorresponding to a time of occurrence of the document-transmittingtransaction.

Also, the transaction input 520 may include at least one of (i)information on personnel with a document-viewing permission representingwho has the document-viewing permission of the document, (ii) a previousdocument-transmitting transaction function value created by applying thespecific operation to each previous document-transmitting transactionwhich is referred to by the document-transmitting transaction, (iii) anoutput index of said each previous document-transmitting transaction,and (iv) at least one signature value of at least one documenttransmitter who transmitted the document.

As an example of the transaction input, the transaction input mayinclude the document information, wherein the document informationincludes an issuance time and date of the document, a type of thedocument, a title of the document, a document-information function valuecreated by applying the specific operation to the information on theoriginal document, information on the document issuance requester whorequested the document, a unique identifier of the document, informationon the document-issuing institution, information on a document-issuingperson in charge of issuing the document, information on authenticity ofthe document, and the access information on the document. Herein, theinformation on the document issuance requester may include a name of thedocument issuance requester and an identifier of the document issuancerequester. Preferably, the identifier of the document issuance requestermay be a universally unique identifier (UUID).

As another example of the transaction input, implemented alone or incombination with the aforementioned example of the transaction input,the transaction input may further include at least one piece ofadditional document information, wherein the additional documentinformation includes (i) a transaction ID representing information on alocation of the document-transmitting transaction function value,created by applying the specific operation to the document-transmittingtransaction, in the blockchain database, (ii) a content section, and(iii) a signature section. Herein, the content section may include apublic key of an author of the additional document information, atime-stamp corresponding to a time of creation of the additionaldocument information, and a comment added by the author of theadditional document information. Also, the signature section may includea signature value created by signing the content section with a privatekey of the author of the additional document information.

By referring to FIG. 6, as still another example of the transactioninput, implemented alone or in combination with the aforementionedexamples of the transaction input, the previous document-transmittingtransaction function value included in the document-transmittingtransaction 600, corresponding to an issuance of the document, among thedocument-transmitting transactions, may be a null function value 622,and a signature value of said at least one document transmitter may be asignature value 626 of the document-issuing institution wherein thesignature value of said at least one document transmitter is included inthe document-transmitting transaction 600. This is because nodocument-transmitting transaction of the document exists, before thedocument-transmitting transaction corresponding to the issuance. FIG. 6includes the document information 624, and this is because thedocument-transmitting transaction 600 corresponds to the issuance of thedocument and the document-transmitting transaction has to include thecontents of the document.

Next, the redeeming condition-determining code 540 in accordance withthe present disclosure may be the smart contract, where the smartcontract may be a source code which is compiled into bytecodes capableof an execution on at least one computing device. And the smart contractin accordance with the present disclosure may be configured to performthe management of the document according to whether the redeemingcondition is satisfied, at a time of the execution, and wherein anintegrity resulting from the execution may be verified by a consensusoutputted from the at least one computing device.

Meanwhile, the redeeming condition may be at least one of (i) one ormore document-transmitting and document-viewing conditions, (ii) one ormore document restriction conditions, and (iii) a document fee-chargingcondition.

More specifically, the document-transmitting and document-viewingconditions may include at least one of (i) a condition for allowing thedocument to be viewed by at least one person, (ii) a condition forallowing transmission of the document to a third party, (iii) acondition for requiring a document-viewing person to log a fact that thedocument-viewing person viewed the document, (iv) a condition forrequiring the document-viewing person to log a fact that thedocument-viewing person confirmed a content of the document, (v) acondition for restricting the document to be viewed by at least onepredetermined specific entity only, (vi) a condition for restricting thedocument to be viewed by one or more entities belonging to apredetermined specific party only, (vii) a condition for preventing atleast one predetermined certain entity from viewing the document, (viii)a condition for restricting the document to be viewed only if at leastone predetermined particular entity allowed the document to be viewed,and (ix) a condition for restricting the number of the transmission ofthe document to be less than a predetermined number. Those skilled inthe art may assume other restricting conditions on the transmission andthe view, in addition to such conditions.

And the document restriction conditions may include at least one of (i)a condition for preventing the information on the original document frombeing printed, and (ii) a condition for allowing transmission of theinformation on the original document via e-mails, but those skilled inthe art understand that the scope of the present disclosure is notlimited thereto.

Also, the document fee-charging condition may be for charging a fee onat least one of the issuance, the view, and the revocation of thedocument, but those skilled in the art also understand that the scope ofthe present disclosure is not limited thereto.

And the aforementioned transaction output 530 may include an address ofat least one document recipient, a name of the document recipient, andan identifier of the document recipient. This is similar to a fact that,in general, when a function value of a transaction is stored in theblockchain of the virtual currency as a result of buying and selling thevirtual currency, who the buyer of the virtual currency is may beconfirmed by recording an address of the recipient of part of thevirtual currency in the transaction. Herein, the address of said atleast one document recipient may be each public key of each documentrecipient.

Next, the method for viewing the document, which is issued in accordancewith the first example embodiment of the present disclosure asaforementioned, is disclosed.

By referring to FIG. 3 again, in the method for viewing the document inaccordance with the first example embodiment of the present disclosure,first, a document-viewing request, including the access information, forthe document may be acquired from the document-viewing requester at astep of S345. If the document-viewing request is acquired, thedocument-managing server may determine whether a document-viewingpermission for the document is granted to the document-viewing requesterat a step of S350. For reference, the order of the step of determiningwhether the document-viewing permission is granted is not limited to theorder described in the present specification, and the step may beperformed after the document generation step of S305.

Whether the document-viewing permission is granted to thedocument-viewing requester may be determined by referring to at leastone of (i) a document-transmitting and document-viewing condition of aredeeming condition-determining code included in a lastdocument-transmitting transaction among the document-transmittingtransactions, and (ii) information on the personnel with thedocument-viewing permission in a transaction input included in the lastdocument-transmitting transaction.

As one example, if the information on the personnel with thedocument-viewing permission of the transaction input does not includethe document-viewing requester, then the document-viewing permission maybe determined as not given to the document-viewing requester.

As another example compatible with this example, whether thedocument-viewing permission is granted to the document-viewing requestermay be determined by referring to the document-transmitting anddocument-viewing condition of the redeeming condition-determining codeincluded in the last document-transmitting transaction among thedocument-transmitting transactions.

By referring to FIG. 3 again, the method for viewing the document inaccordance with the first example embodiment of the present disclosuremay further include steps as follows: if the document-viewing permissionis determined as granted to the document-viewing requester, thedocument-managing server transmits the access information for accessingthe document to the blockchain database or another database at a step ofS355, to thereby instruct the blockchain database or said anotherdatabase to provide the information on the original document,corresponding to the access information, to the document-managing serveror to another device connected with the document-managing server at astep of S360, and if the information on the original document isacquired, the document-managing server displays or supports anotherdevice to display the information on the original document to thedocument-viewing requester at a step of S370.

In the method for viewing the document as such, the document-viewingrequester is described as the last recipient of the document thus far,however, if the document-viewing requester is different from the lastrecipient of the document thus far, the transmission of the document mayneed to be performed beforehand which transfers the managementpermission of the document to the document-viewing requester.

Therefore, the method for viewing the document in accordance with thepresent disclosure with a few additional steps is shown in FIG. 4.

FIG. 4 is a sequence diagram schematically illustrating another exampleembodiment where the document issuance requester provides accessinformation at a step of S444, for accessing the issued document, to thedocument-viewing requester of the method for issuing and viewing thedocument in accordance with the present disclosure. The steps indicatedwith similar reference numerals in FIGS. 3 and 4 are steps forperforming identical or practically identical processes.

In the method for viewing the document in accordance with the firstexample embodiment of the present disclosure, the document-viewingrequest including the access information is acquired from thedocument-viewing requester different from the last recipient of thedocument thus far at the aforementioned step of S345, and the method forviewing the document may further include processes of S455 to S470corresponding to the aforementioned steps of S355 to S370 as follows: acontent of an additional document-transmitting transaction is generatedat a step of S451 which is a document-transmitting transaction thattransfers the management permission of the document, with the lastrecipient of the document thus far as the transmitter of the documentand with the document-viewing requester as the recipient of thedocument, and the access information and the additionaldocument-transmitting transaction are transmitted to the blockchaindatabase, to thereby allow the blockchain database to provide theinformation on the original document itself or its processed one,corresponding to the access information, to the document-managing serverat a step of S455, and to store the additional document-transmittingtransaction in the blockchain database itself.

FIGS. 7A to 7C are conceptual diagrams for comparing a configuration ofthe additional document-transmitting transaction, a configuration of thedocument-transmitting transaction created at a time of the issuance ofthe document as aforementioned, and a configuration of thedocument-transmitting transaction created at a time of the revocation ofthe document to be described later.

By referring to FIG. 7A, the transaction input of the additionaldocument-transmitting transaction as such may include a value created byapplying the specific operation to a last document-transmittingtransaction as a previous document-transmitting transaction functionvalue, because the additional document-transmitting transaction is not adocument-transmitting transaction corresponding to the initial issuanceof the document and thus at least one document-transmitting transactionto be referred to is present. For reference, since the documentinformation may be added if the document-viewing requester desires, itis shown as an optional element in FIG. 7A.

An additional input of the document-viewing requester may be stored inthe additional document-transmitting transaction. That is, at theprocesses of S451 and S455, if the additional input from thedocument-viewing requester is acquired, the document-managing server mayincorporate additional document information into the additionaldocument-transmitting transaction, such that a content section of theadditional document information includes the additional input.

For reference, for comparison of FIG. 7A aforementioned and FIG. 7C tobe described later, FIG. 7B shows a document-transmitting transactionwhich is same as the document-transmitting transaction at the time ofthe issuance shown in FIG. 6.

Next, the method for revoking the document which is issued in accordancewith the first example embodiment of the present disclosure is describedby referring to FIG. 7C.

As aforementioned, FIG. 7C is a conceptual diagram schematicallyillustrating a configuration of the document-transmitting transactiongenerated at the time of revoking the document.

By referring to FIG. 7C, the revocation of the document is performed bythe generation of the document-transmitting transaction which transfersthe management permission of the document, with an address forrevocation as the address of the recipient. Therefore, the revocation isperformed similarly to what is described of the additionaldocument-transmitting transaction.

Specifically, the method for revoking the document based on theblockchain in accordance with the first example embodiment of thepresent disclosure may include steps (not illustrated) as follows: oncondition that the information on the original document including thedocument itself or its processed one of the document has been issued inresponse to the document-issuing request from the document issuancerequester, and at least one document-transmitting transaction functionvalue created by applying the specific operation to at least onedocument-transmitting transaction has been stored in the blockchaindatabase where the document-transmitting transaction has either (i) thedocument-issuing institution as the transmitter of the document and thedocument issuance requester as the last recipient of the document thusfar, or (ii) a first specific recipient as the transmitter of thedocument and a second specific recipient as the last recipient of thedocument thus far, if a document-revoking request including the accessinformation for accessing the document is acquired from the documentrevocation requester, the document-managing server determines whether adocument-revoking permission for the document is granted to the documentrevocation requester.

As one example, the document-revoking permission may be determined asheld by an entity who has the management permission of the document. Asa result, the last recipient of the document thus far may have apermission to revoke the document.

As another example, a certain kind of documents may be prearranged suchthat a document-issuing person in charge within the document-issuinginstitution has the document-revoking permission of said certain kind ofdocuments. For example, according to legal merits to revoke thedocuments including government secrets, in the method for revoking thedocument in accordance with the present disclosure, a person in chargewithin the government may be set as having the revocation permission torevoke the documents at once.

Next, the method for revoking the document in accordance with the firstexample embodiment of the present disclosure may further include steps(not illustrated) as follows: if the revocation permission is determinedas granted to the document revocation requester, the document-managingserver transmits a document-revoking transaction which is adocument-transmitting transaction for transferring the managementpermission of the document to the blockchain database with the lastrecipient of the document thus far as the transmitter of the documentand with the address for revocation as an address of the recipient ofthe document, to thereby allow the blockchain database to store adocument-revocation function value, created by applying the specificoperation to the document-revoking transaction, in the blockchain.

Herein, a private key corresponding to the address for revocation may bedestroyed on purpose, to prevent recovering a revoked document bytransmitting the revoked document to another recipient.

Meanwhile, the private key corresponding to the address for revocationmay be retained by a managing entity, to allow recovering the revokeddocument by transmitting the revoked document to another recipient. Forexample, such a managing entity may be the document-issuing institution,which operates the document-managing server or the document-issuingserver, however, the managing entity may be still another entity.

So far, a single document-viewing requester is assumed in thedescription of the present disclosure, however, the document recipientwho requests viewing of the document may be one or more, and thedocument transmitter, as the managing entity of the document, who wantsto transmit the document to at least one document recipient may also beone or more.

For reference, FIGS. 8A to 8C are conceptual diagrams for comparing aconfiguration of the document-transmitting transaction in which thedocument is transferred to a single document recipient by agreement ofmultiple document transmitters, a configuration of thedocument-transmitting transaction in which the document is transferredto multiple document recipient from a single document transmitter, and aconfiguration of the document-transmitting transaction in which thedocument is transferred to the multiple document recipient from themultiple document transmitters.

At the time of requesting the issuance of the document, the singledocument issuance requester or multiple document issuance requesters maydesignate the document recipient who initially receives the managementpermission of the document as a single person or multiple persons, andthis is practically same as a principle of receiving one or more UTXOsas input and outputting one or more UTXOs as merged/split outputs.

First, FIG. 8A schematically illustrates the configuration of thedocument-transmitting transaction in which the document is transferredto the single document recipient by the agreement of the multipledocument transmitters.

The multiple document transmitters may be referred to by the informationon the personnel with the document-viewing permission, where theinformation on the personnel may be one of inputs included in thedocument-transmitting transaction, and past document-transmittingtransactions corresponding to the document whose management permissionis held by the multiple document transmitters may be referred to by theprevious document-transmitting transaction function value which is oneof the transaction inputs. Each signature value of the multiple documenttransmitters may also be included in the transaction input, asschematically illustrated in FIG. 8A.

Next, FIG. 8B schematically illustrates the configuration of thedocument-transmitting transaction in which the document is transferredfrom the single document transmitter to the multiple documentrecipients.

Herein, outputs of the document-transmitting transaction may include theaddresses, for example, public keys, of the multiple documentrecipients, and as previously described in the configuration of thedocument-transmitting transaction, may also include a name and anidentifier of at least one of the multiple document recipient.

Next, since the configuration of the document-transmitting transactionshown in FIG. 8C is similar to a combination of the aforementionedconfigurations shown in FIGS. 8A and 8B, those skilled in the artunderstand the case of FIG. 8C by referring to the description of FIGS.8A and 8B.

Next, FIG. 9 is a drawing schematically illustrating a process ofviewing history of entire document-transmitting transactions.

By referring to FIG. 9, since every document-transmitting transactionexcept the document-transmitting transaction TRXID1 corresponding to theinitial issuance, refers to its corresponding previousdocument-transmitting transaction using its function value thus, theTRXID1, a TRXID2, and a TRXID3, that is, every document-transmittingtransaction generated with regard to the document may be tracked andmanaged by referring to the respective previous document-transmittingtransaction function values of the individual document-transmittingtransactions, simply using information on the last document-transmittingtransaction only, for example, the TRXID3. That is, the history of theentire document-transmitting transactions may be viewed.

Second Example Embodiment

Next, the method for issuing the document based on the blockchain inaccordance with the second example embodiment of the present disclosureis described as follows. Below, the technological characteristicsidentical to those of the aforementioned first example embodiment willbe omitted, and only specific details will be disclosed. The blockchainof the first example embodiment may correspond to a first blockchain ofthe second example embodiment, and the second example embodiment furtherdescribes connection of the first blockchain with the second blockchain.

By referring to FIG. 3 again, the method for issuing the document inaccordance with the second example embodiment of the present disclosuremay include steps as follows: the document-managing server allows theblockchain database to store the document-transmitting transaction hashvalue in the first blockchain at a process of S330, and if one ofanchoring conditions is satisfied, allows the blockchain database tostore a representative hash value or its processed value in the secondblockchain at a process of S330′ (not illustrated) where therepresentative hash value is calculated by using both (i) a specifichash value which is the document-transmitting transaction hash value and(ii) its at least one corresponding neighboring hash value which is ahash value of a specific document-transmitting transaction differentfrom the document-transmitting transaction.

The calculation by using both the specific hash value and at least oneof the neighboring hash values may be performed by various functions.Supposing that the specific hash value is an input, and that theneighboring hash values are x1, x2, . . . , xn, then a representativehash value t may be expressed as a following equation.<Equation 1>t=hash(function(input, x1, x2, . . . , xn))

Herein, the document-managing server or the blockchain database mayrecord and manage the specific hash value and its corresponding at leastone neighboring hash value in a certain data structure. Herein, the datastructure may vary and one example may be a Merkle tree. In this case,the calculation using both (i) the specific hash value and (ii) at leastone hash value of at least one neighboring node which corresponds to anode of the specific hash value may be performed by using the Merkletree.

That is, the document-managing server or the blockchain database mayperform or support another device to perform processes of (i) a processof creating at least one Merkle tree by allotting the specific hashvalue to its leaf node, and (ii) a process of recording, if one of theanchoring conditions is satisfied, the representative hash value or itsprocessed value calculated by using both (ii-1) the specific hash valueof a specific leaf node and (ii-2) at least one hash value allocated toat least one of other leaf nodes corresponding to the specific leafnode, in the second blockchain.

The document-managing server or the blockchain database may record thehash value allocated to the root node as the representative hash valuein the second blockchain. Herein, a processed value of therepresentative hash value may be recorded. For example, a resultantvalue from hex operation on the representative hash value may berecorded.

Meanwhile, a first data structure and a second data structure may beconnected in a form of a chain, if the document-managing server or theblockchain database stores the specific hash value and the at least oneneighboring hash value in the first data structure and then stores andmanages the second data structure identical in a form to the first datastructure.

Especially, as the example aforementioned, if the first data structureand the second data structure are Merkle trees, a root value of thefirst data structure or a hash value of the root value may be allocatedto a first leaf node of the second data structure.

Moreover, data integrity may be further ensured by verifying the firstdata structure when the second data structure is created.

Further, if the Merkle tree is a first tree among two or more Merkletrees linked in chains, a hash value or its processed value of a messagedata, which includes text, numbers or symbols, may be allocated to afirst leaf node of the Merkle tree. For example, at the time of creationof the Merkle tree, a hash value of an input message initially given bythe document-managing server or the blockchain database may beallocated.

FIGS. 10 and 11 are drawings illustrating an example of a Merkle treecreated in accordance with the present disclosure.

FIG. 10 illustrates a Merkle tree with four (two to the power of two)leaf nodes. As the illustrated Merkle tree is a first Merkle tree whosetree_id is zero, a hash value sha256(PrivBC_unique_message) ofPrivBC_unique_message is allocated to an h0 node which is a first leafnode. If transactions are being recorded, the document-managing serveror the blockchain database may create a leaf node next to a last leafnode of the Merkle tree currently being configured and may allocate thespecific hash value or its processed value to the created leaf node. Forexample, if an allocation of values is completed with the h1 node as alast which is a second leaf node of the Merkle tree in FIG. 10, and if anew leaf node is to be created, then an h2 node which is a next leafnode may be created and the specific hash value or its processed valuesha256(input2) may be allocated to the h2 node. Further, thedocument-managing server or the blockchain database may calculate orsupport another device to calculate by using both (i) a specific hashvalue and (ii) a hash value allocated to an h3 node which is a siblingnode of the h2 node which is a third leaf node to which the specifichash value is allocated. The hash value of the calculated value abovemay be allocated to an h23 node which is a parent node of the h2 nodeand the h3 node. Since the parent node, i.e., the h23 node, is not theroot node of the Merkle tree, the document-managing server or theblockchain database may repeat the processes by regarding the hash valueallocated to the h23 node as the specific hash value. That is, with thehash value allocated to the h23 node as a specific hash value, the hashvalues allocated to the h23 node and an h01 node may be used together tobe calculated and allocated to an h0123 node which is a parent node ofthe h23 node and the h01 node. Herein, as the h0123 node is the rootnode, the document-managing server or the blockchain database may recordthe processed value hex(h{node_index}) of the hash value allocated tothe h0123 node in the second blockchain.

To explain this in a recursive way, if one of the anchoring conditionsis satisfied, the document-managing server or the blockchain databasemay (x1) calculate an intermediate value by using (i) the specific hashvalue and (ii) a hash value allocated to a sibling node of the specificleaf node, and then allocate a hash value of the intermediate value to aparent node of the specific leaf node, (x2) record the hash value of theintermediate value in the second blockchain as the representative hashvalue if the parent node is a root node of the Merkle tree, and (x3)repeat steps from (x1) to (x3) by regarding the hash value of theintermediate value as the specific hash value and regarding the parentnode as the specific leaf node if the parent node is not the root node.

Meanwhile, the anchoring conditions may include one of (i) a conditionthat a certain number of the specific hash value and the neighboringhash value are acquired or generated, (ii) a condition that a certainamount of time is elapsed, (iii) a condition that a block is created inthe first blockchain, and (iv) a condition that has at least one ofcharacteristics of services.

In the second example embodiment, if the hash values including thedocument-transmitting transaction hash value are acquired as many as thenumber of the leaf nodes, then each of the hash values including thedocument-transmitting transaction hash value may be each input value,i.e., each value allocated to each of the leaf nodes, to theaforementioned Merkle tree.

Also, the document-managing server or the blockchain database may createa root value of the Merkle tree aforementioned at stated intervals, byreferring to the condition (ii) above. In this case, if a certain amountof time is elapsed, the document-managing server or the blockchaindatabase may create the Merkle tree by referring to input values by thetime, and may record the root value of the Merkle tree on the secondblockchain.

However, in this case, no value may be allocated to a sibling node ofthe node to which the specific hash value is allocated even though thecertain amount of time is elapsed. In case no hash value is allocated tothe sibling node even though one of the anchoring conditions issatisfied, the document-managing server or the blockchain database mayallocate a certain hash value to the sibling node to thereby produce aroot value of the Merkle tree by the method aforementioned. For example,the document-managing server or the blockchain database may copy andallocate the specific hash value to the sibling node.

The characteristics of services may be at least part of (i) informationon cost paid by entities who use the document management method or thedocument-managing server in accordance with the present disclosure, (ii)information on a time-zone during which recording of thedocument-transmitting transaction or its hash value is performed, (iii)information on a location where the recording of the transaction isperformed, and (iv) information on a type of a person or a company whichis a managing entity of a server involved in the recording, for example,the document-managing server, the document-issuing server, thedocument-storing device, etc. However, the scope of the presentdisclosure is not limited thereto.

Meanwhile, if a creation of a new Merkle tree starts and if one of theanchoring conditions is satisfied with no document-transmittingtransaction having been received, the document-managing server or theblockchain database may create the new Merkle tree by allotting certainmessage data to its first and second leaf nodes and may record the rootvalue of the new Merkle tree or its processed value in the secondblockchain. In this case, the new Merkle tree with two leaf nodes may becreated.

Meanwhile, a first data structure and a second data structure may beconnected in a form of a chain, if the document-managing server or theblockchain database stores the specific hash value and the at least oneneighboring hash value in the first data structure and then stores andmanages the second data structure identical in a form to the first datastructure as aforementioned. Especially, if the first data structure andthe second data structure are Merkle trees, a root value of the firstdata structure or a hash value of the root value may be allocated to afirst leaf node of the second data structure.

FIG. 11 is a drawing illustrating an example of a Merkle tree created ina form of the second data structure in accordance with the presentdisclosure.

By referring to FIG. 11, it is clear that the root value hex(h0123) ofthe Merkle tree whose tree_id is zero in FIG. 10 is allocated to thefirst leaf node which is an h4 node of a new Merkle tree. In such amanner, the present disclosure has advantage of improving dataintegrity, as tracking becomes easier even in a case of data forgery, byconnecting multiple data structures created when a document-transmittingtransaction occurs.

Also, the method for issuing the document in accordance with the secondexample embodiment of the present disclosure may further include a step(not illustrated) as follows: the document-managing server verifiesintegrity of the first blockchain by comparing periodically or inresponse to a request from the managing entity (i) a firstrepresentative hash value or its processed value calculated by usingboth (i-1) a hash value of at least one document-transmittingtransaction recorded in the first blockchain and (i-2) its correspondingat least one neighboring hash value and (ii) its corresponding secondrepresentative hash value or its processed value recorded in the secondblockchain.

Although the step of verifying the integrity of the blockchain isdescribed from a perspective of the method for issuing the document, thestep may be applied to the method for viewing the document or to themethod for revoking the document in a same manner.

As one example, the first blockchain and the second blockchain may be aprivate blockchain or a public blockchain. Herein, the first blockchainmay be the private blockchain database and the second blockchain may bethe public blockchain database.

Next, the method for viewing the issued document in accordance with thesecond example embodiment of the present disclosure is explained, butthe technological characteristics identical to those of theaforementioned first example embodiment will be omitted, and onlyspecific details will be disclosed.

By referring to FIG. 4 again, a case is described where the documentissuance requester provides the access information at the step of S444,for accessing the issued document, to the document-viewing requester, inthe method for viewing the issued document in accordance with the secondexample embodiment of the present disclosure.

In the method for viewing the document in accordance with the secondexample embodiment of the present disclosure, if the document-viewingrequest for the document including the access information is acquiredfrom the document-viewing requester different from the last recipient ofthe document thus far, a content of the additional document-transmittingtransaction is generated at a step of S451, the access information ofthe document and the additional document-transmitting transaction aretransmitted to the blockchain database, to thereby allow the blockchaindatabase to provide the document-managing server with the information onthe original document including the document itself or its processed onecorresponding to the access information for the document and to recordthe additional document-transmitting transaction in the first blockchainat a step of S455, and if one of the anchoring conditions is satisfied,allows the blockchain database to store a representative hash value orits processed value in the second blockchain at a process of S455′ (notillustrated) where the representative hash value is calculated by usingboth (i) a specific hash value which is the additionaldocument-transmitting transaction hash value and (ii) its at least onecorresponding neighboring hash value which is a hash value of a specificdocument-transmitting transaction different from the additionaldocument-transmitting transaction.

Next, the method for revoking the document which is issued in accordancewith the second example embodiment of the present disclosure isdescribed. Specifically, the method for revoking the document based onthe blockchain in accordance with the second example embodiment of thepresent disclosure may include steps as follows: along with storing ofthe document-transmitting transaction hash value in the firstblockchain, if one of the android conditions is satisfied, theblockchain database is instructed to store a representative hash valueor its processed value in the second blockchain where the representativehash value is calculated by using both (i) a specific hash value whichis a document-revoking transaction hash value and (ii) its at least onecorresponding neighboring hash value which is a hash value of a specificdocument-transmitting transaction different from the document-revokingtransaction.

The present disclosure has an effect of improving reliability andsecurity of a document management system by preventing unauthorized copyor forgery in addition to strong non-repudiation and prevention offalsification, in all of the aforementioned embodiments of the presentdisclosure.

Advantages of the technique disclosed herein with the above embodimentsare guarantees of reliability of the document management system byessentially blocking forgery of document-related information, such aspublic keys, hash values, etc., and enhancement of integrity throughprevention of errors in the document management by allowing recordationof transactions in the blockchain.

The present disclosure has an effect of strictly managing permissionrequired for issuing, viewing, and revoking a document by using a smartcontract, to thereby prevent an unauthorized person from generating,viewing, and revoking the document. In other words, the presentdisclosure has an effect of providing a function for non-repudation, byconfirming that the document is generated by an authorized person anddistributed without tampering once the document is issued.

The present disclosure has another effect of periodically verifying anauthenticity of an electronic document, to thereby guarantee that theelectronic document is not forged or falsified.

The present disclosure has still another effect of guaranteeingsecurity, by forcing every entity participating in issuing, viewing andrevoking of the electronic document to use cryptographical technologieslike a public key-private key pair algorithm, e.g., RSA, ECC, and hashfunctions, etc.

Based on the explanation of the above embodiments, those skilled in theart can clearly understand that the present disclosure may beimplemented by combination of software and hardware or hardware alone.The part contributing to the prior art or the object of a technicalsolution of the present disclosure may be implemented in a form ofexecutable program command through a variety of computer components andmay be recorded in computer readable media. The computer readable mediamay include solely or in combination, program commands, data files, anddata structures. The program commands recorded to the media may becomponents specially designed for the present invention or may be knownand usable to a skilled human in a general field. Computer readablemedia include magnetic media such as hard disk, floppy disk, andmagnetic tape, optical media such as CD-ROM and DVD, magneto-opticalmedia such as floptical disk and hardware devices such as ROM, RAM, andflash memory specially designed to store and carry out program commands.Program commands may include not only a machine language code made by acomplier but also a high level code that can be used by an interpreteretc., which is executed by a computer. The aforementioned hardwaredevice can work as more than a software module to perform the action ofthe present disclosure and they can do the same in the opposite case.The hardware device may include a processor such as a CPU or a GPU,combined with a memory device such as ROM or RAM to store the programcommands, configured to execute the commands stored in the memory, and acommunication part which can exchange signals with external devices. Inaddition, the hardware device may include a keyboard, a mouse, and anyother external input device to receive commands prepared by developers.

As seen above, the present disclosure has been explained by specificmatters such as detailed components, limited embodiments, and drawings.They have been provided only to help more general understanding of thepresent disclosure. It, however, will be understood by those skilled inthe art that various changes and modification may be made from thedescription without departing from the spirit and scope of thedisclosure as defined in the following claims.

Accordingly, the thought of the present disclosure must not be confinedto the explained embodiments, and the following patent claims as well aseverything including variations equal or equivalent to the patent claimspertain to the category of the thought of the present disclosure.

What is claimed is:
 1. A method for issuing a document based on ablockchain, comprising steps of: (a) when a document-issuing requestfrom a document issuance requester is acquired, instructing, by adocument-managing server, a document-issuing server of adocument-issuing institution which has an issuance permission of thedocument to acquire identification information on the document wherein amanagement permission of the document is given to the document-issuinginstitution, and instructing a document-storing device to acquirelocation information representing where the document is generated orstored by referring to the identification information on the document,to thereby acquire information on an original document including thedocument itself or information on a state of the processed documentwhich is generated or stored as corresponding to the locationinformation; and (b) (i) generating, by the document-managing server,contents of a document-transmitting transaction representing a transferof the management permission of the document from the document-issuinginstitution as a transmitter of the document to the document issuancerequester as a recipient of the document, and transmitting thedocument-transmitting transaction to a blockchain database, to therebyinstruct the blockchain database to store a document-transmittingtransaction function value, created by applying a specific operation tothe document-transmitting transaction, in the blockchain databaseitself, and (ii) displaying, by the document-managing server, orsupporting another device connected with the document-managing server todisplay, access information, to be used for accessing an issuance resultof the document and the information on the original document, to thedocument issuance requester, wherein the document-transmittingtransaction includes header information, a transaction input, atransaction output, and at least one redeeming condition-determiningcode configured to determine at least one redeeming condition, whereinthe redeeming condition is at least one of one or moredocument-transmitting and document-viewing conditions, one or moredocument restriction conditions, and a document fee-charging condition.2. The method of claim 1, wherein the step of (b) further includes aprocess of: (iii) the document-managing server transmitting theinformation on the original document to the blockchain database oranother database connected with the document-managing server, to therebyallow the blockchain database or said another database to retain theinformation on the original document.
 3. The method of claim 1, wherein,at the process of in the step of (b), the access information isretrieved from the blockchain database.
 4. The method of claim 1,wherein the header information includes transaction version information,transaction type information, and a time-stamp corresponding to a timeof occurrence of the document-transmitting transaction.
 5. The method ofclaim 1, wherein the transaction input includes at least one of (i)information on personnel with a document-viewing permission representingwho has the document-viewing permission of the document, (ii) a previousdocument-transmitting transaction function value created by applying thespecific operation to each previous document-transmitting transactionwhich is referred to by the document-transmitting transaction, (iii) anoutput index of said each previous document-transmitting transaction,and (iv) at least one signature value of at least one documenttransmitter who transmitted the document.
 6. The method of claim 5,wherein the transaction input further includes document information, andwherein the document information includes an issuance time and date ofthe document, a type of the document, a title of the document, adocument-information function value created by applying the specificoperation to the information on the original document, information onthe document issuance requester who requested the document, a uniqueidentifier of the document, information on the document-issuinginstitution, information on a document-issuing person in charge ofissuing the document, information on authenticity of the document, andthe access information on the document.
 7. The method of claim 6,wherein the information on the document issuance requester includes aname of the document issuance requester and an identifier of thedocument issuance requester, and wherein the identifier of the documentissuance requester is a universally unique identifier (UUID).
 8. Themethod of claim 5, wherein the transaction input further includes atleast one piece of additional document information, and wherein theadditional document information includes (i) a transaction IDrepresenting information on a location of the document-transmittingtransaction function value, created by applying the specific operationto the document-transmitting transaction, in the blockchain database,(ii) a content section, and (iii) a signature section.
 9. The method ofclaim 8, wherein the content section includes a public key of an authorof the additional document information, a time-stamp corresponding to atime of creation of the additional document information, and a commentadded by the author of the additional document information, and whereinthe signature section includes a signature value created by signing thecontent section with a private key of the author of the additionaldocument information.
 10. The method of claim 5, wherein the previousdocument-transmitting transaction function value included in thedocument-transmitting transaction corresponding to an issuance of thedocument is a null function value, and wherein the signature value ofsaid at least one document transmitter is a signature value of thedocument-issuing institution, and wherein the signature value of said atleast one document transmitter is included in the document-transmittingtransaction.
 11. The method of claim 1, wherein the redeemingcondition-determining code is a smart contract, wherein the smartcontract is (i) a source code which is compiled into bytecodes capableof an execution on at least one computing device, (ii) configured toperform management of the document according to whether the redeemingcondition is satisfied, at a time of the execution, and wherein anintegrity resulting from the execution is verified by a consensusoutputted from the computing device.
 12. The method of claim 1, whereinthe document-transmitting and document-viewing conditions include atleast one of (i) a condition for allowing the document to be viewed byat least one person, (ii) a condition for allowing transmission of thedocument to a third party, (iii) a condition for requiring adocument-viewing person to log a fact that the document-viewing personviewed the document, (iv) a condition for requiring the document-viewingperson to log a fact that the document-viewing person confirmed acontent of the document, (v) a condition for restricting the document tobe viewed by at least one predetermined specific entity only, (vi) acondition for restricting the document to be viewed by one or moreentities belonging to a predetermined specific party only, (vii) acondition for preventing at least one predetermined certain entity fromviewing the document, (viii) a condition for restricting the document tobe viewed only if at least one predetermined particular entity allowedthe document to be viewed, and (ix) a condition for restricting thenumber of the transmission of the document to be less than apredetermined number.
 13. The method of claim 1, wherein the documentrestriction conditions include at least one of (i) a condition forpreventing the information on the original document from being printed,and (ii) a condition for allowing transmission of the information on theoriginal document via e-mails.
 14. The method of claim 1, wherein thedocument fee-charging condition is for charging a fee on at least one ofan issuance, a view, and a revocation of the document.
 15. The method ofclaim 1, wherein the transaction output includes an address of at leastone document recipient, a name of the document recipient, and anidentifier of the document recipient.
 16. A document-managing server forissuing a document based on a blockchain, comprising: a transceiver foracquiring a document-issuing request from a document issuance requester;and a processor configured to execute instructions to perform or supportanother device to perform processes of: (I) instructing adocument-issuing server of a document-issuing institution which has anissuance permission of the document to acquire identificationinformation on the document wherein a management permission of thedocument is given to the document-issuing institution, and instructing adocument-storing device to acquire location information representingwhere the document is generated or stored by referring to theidentification information on the document, to thereby acquireinformation on an original document including the document itself or itsprocessed one which is generated or stored as corresponding to thelocation information and (II) (i) generating contents of adocument-transmitting transaction representing a transfer of themanagement permission of the document from the document-issuinginstitution as a transmitter of the document to the document issuancerequester as a recipient of the document, and transmitting thedocument-transmitting transaction to a blockchain database, to therebyinstruct the blockchain database to store a document-transmittingtransaction function value, created by applying a specific operation tothe document-transmitting transaction, in the blockchain databaseitself, and (ii) displaying or supporting another device connected withthe document-managing server to display access information, to be usedfor accessing an issuance result of the document and the information onthe original document, to the document issuance requester, wherein thedocument-transmitting transaction includes header information, atransaction input, a transaction output, and at least one redeemingcondition-determining code configured to determine at least oneredeeming condition, wherein the redeeming condition is at least one ofone or more document-transmitting and document-viewing conditions, oneor more document restriction conditions, and a document fee-chargingcondition.
 17. The document-managing server of claim 16, wherein theprocess of (II) further includes a process of: (iii) transmitting theinformation on the original document to the blockchain database oranother database connected with the document-managing server, to therebyallow the blockchain database or said another database to retain theinformation on the original document.
 18. The document-managing serverof claim 16, wherein, at the process of (ii), the access information isretrieved from the blockchain database.
 19. A method for issuing adocument based on a blockchain, comprising steps of: (a) when adocument-issuing request from a document issuance requester is acquired,instructing, by a document-managing server, a document-issuing server ofa document-issuing institution which has an issuance permission of thedocument to acquire identification information on the document wherein amanagement permission of the document is given to the document-issuinginstitution; and instructing a document-storing device to acquirelocation information representing where the document is generated orstored by referring to the identification information on the document,to thereby acquire information on an original document including thedocument itself or information on a state of the processed documentwhich is generated or stored as corresponding to the locationinformation; and (b) (i) generating, by the document-managing server,contents of a document-transmitting transaction representing a transferof the management permission of the document from the document-issuinginstitution as a transmitter of the document to the document issuancerequester as a recipient of the document, and transmitting thedocument-transmitting transaction to a blockchain database, to therebyinstruct the blockchain database to store a document-transmittingtransaction function value, created by applying a specific operation tothe document-transmitting transaction, in the blockchain databaseitself, and (ii) displaying, by the document-managing server, orsupporting another device connected with the document-managing server todisplay, access information, to be used for accessing an issuance resultof the document and the information on the original document, to thedocument issuance requester, wherein the document-transmittingtransaction includes header information, a transaction input, atransaction output, and at least one redeeming condition-determiningcode configured to determine at least one redeeming condition, whereinthe transaction input includes at least one of (i) information onpersonnel with a document-viewing permission representing who has thedocument-viewing permission of the document, (ii) a previousdocument-transmitting transaction function value created by applying thespecific operation to each previous document-transmitting transactionwhich is referred to by the document-transmitting transaction, outputindex of said each previous document-transmitting transaction, and (iv)at least one signature value of at least one document transmitter whotransmitted the document, wherein the transaction input further includesdocument information, and wherein the document information includes anissuance time and date of the document, a type of the document, a titleof the document, a document-information function value created byapplying the specific operation to the information on the originaldocument, information on the document issuance requester who requestedthe document, a unique identifier of the document, information on thedocument-issuing institution, information on a document-issuing personin charge of issuing the document, information on authenticity of thedocument, and the access information on the document.
 20. A method forissuing a document based on a blockchain, comprising steps of: when adocument-issuing request from a document issuance requester is acquired,instructing, by a document-managing server, a document-issuing server ofa document-issuing institution which has an issuance permission of thedocument to acquire identification information on the document wherein amanagement permission of the document is given to the document-issuinginstitution, and instructing a document-storing device to acquirelocation information representing where the document is generated orstored by referring to the identification information on the document,to thereby acquire information on an original document including thedocument itself or information on a state of the processed documentwhich is generated or stored as corresponding to the locationinformation; and (b) (i) generating, by the document-managing server,contents of a document-transmitting transaction representing a transferof the management permission of the document from the document-issuinginstitution as a transmitter of the document to the document issuancerequester as a recipient of the document, and transmitting thedocument-transmitting transaction to a blockchain database, to therebyinstruct the blockchain database to store a document-transmittingtransaction function value, created by applying a specific operation tothe document-transmitting transaction, in the blockchain databaseitself, and (ii) displaying, by the document-managing server, orsupporting another device connected with the document-managing server todisplay, access information, to be used for accessing an issuance resultof the document and the information on the original document, to thedocument issuance requester, wherein the document-transmittingtransaction includes header information, a transaction input, atransaction output, and at least one redeeming condition-determiningcode configured to determine at least one redeeming condition, whereinthe transaction input includes at least one of (i) information onpersonnel with a document-viewing permission representing who has thedocument-viewing permission of the document, (ii) a previousdocument-transmitting transaction function value created by applying thespecific operation to each previous document-transmitting transactionwhich is referred to by the document-transmitting transaction, (iii) anoutput index of said each previous document-transmitting transaction,and (iv) at least one signature value of at least one documenttransmitter who transmitted the document, wherein the transaction inputfurther includes at least one piece of additional document information,and wherein the additional document information includes (i) atransaction ID representing information on a location of thedocument-transmitting transaction function value, created by applyingthe specific operation to the document-transmitting transaction, in theblockchain database, (ii) a content section, and (iii) a signaturesection.
 21. A method for issuing a document based on a blockchain,comprising steps of: (a) when a document-issuing request from a documentissuance requester is acquired, instructing, by a document-managingserver, a document-issuing server of a document-issuing institutionwhich has an issuance permission of the document to acquireidentification information on the document wherein a managementpermission of the document is given to the document-issuing institution,and instructing a document-storing device to acquire locationinformation representing where the document is generated or stored byreferring to the identification information on the document, to therebyacquire information on an original document including the documentitself or information on a state of the processed document which isgenerated or stored as corresponding to the location information; and(b) (i) generating, by the document-managing server, contents of adocument-transmitting transaction representing a transfer of themanagement permission of the document from the document-issuinginstitution as a transmitter of the document to the document issuancerequester as a recipient of the document, and transmitting thedocument-transmitting transaction to a blockchain database, to therebyinstruct the blockchain database to store a document-transmittingtransaction function value, created by applying a specific operation tothe document-transmitting transaction, in the blockchain databaseitself, and (ii) displaying, by the document-managing server, orsupporting another device connected with the document-managing server todisplay, access information, to be used for accessing an issuance resultof the document and the information on the original document, to thedocument issuance requester, wherein the document-transmittingtransaction includes header information, a transaction input, atransaction output, and at least one redeeming condition-determiningcode configured to determine at least one redeeming condition, whereinthe transaction input includes at least one of information on personnelwith a document-viewing permission representing who has thedocument-viewing permission of the document, (ii) a previousdocument-transmitting transaction function value created by applying thespecific operation to each previous document-transmitting transactionwhich is referred to by the document-transmitting transaction, (iii) anoutput index of said each previous document-transmitting transaction,and (iv) at least one signature value of at least one documenttransmitter who transmitted the document, wherein the previousdocument-transmitting transaction function Value included in thedocument-transmitting transaction corresponding to an issuance of thedocument is a null function value, and wherein the signature value ofsaid at least one document transmitter is a signature value of thedocument-issuing institution, and wherein the signature value of said atleast one document transmitter is included in the document-transmittingtransaction.
 22. A document-managing server for issuing a document basedon a blockchain, comprising: a transceiver for acquiring adocument-issuing request from a document issuance request; and aprocessor configured to execute instructions to perform or supportanother device to perform processes of: (I) instructing adocument-issuing server of a document-issuing institution which has anissuance permission of the document to acquire identificationinformation on the document wherein a management permission of thedocument is given to the document-issuing institution, and instructing adocument-storing device to acquire location information representingwhere the document is generated or stored by referring to theidentification information on e document, to thereby acquire informationon an original document including the document itself or its processedone which is generated or stored as corresponding to the locationinformation and (II) (i) generating contents of a document-transmittingtransaction representing a transfer of the management permission of thedocument from front the document-issuing institution as a transmitter ofthe document to the document issuance requester as a recipient of thedocument, and transmitting the document-transmitting transaction to ablockchain database, to thereby instruct the blockchain database tostore a document-transmitting transaction function value, created byapplying a specific operation to the document-transmitting transaction,in the blockchain database itself, and (ii) displaying or supportinganother device connected with the document-managing server to displayaccess information, to be used for accessing an issuance result of thedocument and the information on the original document, to the documentissuance requester, wherein the document-transmitting transactionincludes header information, a transaction input, a transaction output,and at least one redeeming condition-determining code configured todetermine at least one redeeming condition, wherein the transactioninput includes at least one of (i) information on personnel with adocument-viewing permission representing who has the document-viewingpermission of the document, (ii) a previous document-transmittingtransaction function value created by applying the specific operation toeach previous document-transmitting transaction which is referred to bythe document-transmitting transaction, (iii) an output index of saideach previous document-transmitting transaction, and (iv) at least onesignature value of at least one document transmitter who transmitted thedocument, wherein the transaction input further includes documentinformation, and wherein the document information includes an issuancetime and date of the document, a type of the document, a title of thedocument, a document-information function value created by applying thespecific operation to the information on the original document,information on the document issuance requester who requested thedocument, a unique identifier of the document, information on thedocument-issuing institution, information on a document-issuing personin charge of issuing the document, information on authenticity of thedocument, and the access information on the document.
 23. Adocument-managing server for issuing a document based on a blockchain,comprising: a transceiver for acquiring a document-issuing request froma document issuance requester; and a processor configured to executeinstructions to perform or support another device to perform processesof: (I) instructing a document-issuing server of a document-issuinginstitution which has an issuance permission of the document to acquireidentification information on the document wherein a managementpermission of the document is given to the document-issuing institution;and instructing a document-storing device to acquire locationinformation representing where the document is generated or stored byreferring to the identification information on the document, to therebyacquire information on an original document including the documentitself or its processed one which is generated or stored ascorresponding to the location information and (II) (i) generatingcontents of a document-transmitting transaction representing a transferof the management permission of the document from the document-issuinginstitution as a transmitter of the document to the document issuancerequester as a recipient of the document, and transmitting thedocument-transmitting transaction to a blockchain database, to therebyinstruct the blockchain database to store a document-transmittingtransaction function value, created by applying a specific operation tothe document-transmitting transaction, in the blockchain databaseitself, and (ii) displaying or supporting another device connected withthe document-managing server to display access information, to be usedfor accessing an issuance result of the document and the information onthe original document, to the document issuance requester, wherein thedocument-transmitting transaction includes header information, atransaction input, a transaction output, and at least one redeemingcondition-determining code configured to determine at least oneredeeming condition, wherein the transaction input includes at least oneof (i) information on personnel with a document-viewing permissionrepresenting who has the document-viewing permission of the document,(ii) a previous document-transmitting transaction function value createdby applying the specific operation to each previousdocument-transmitting transaction which is referred to by thedocument-transmitting transaction, (iii) an output index of said eachprevious document-transmitting transaction, and (iv) at least onesignature value of at least one document transmitter who transmitted thedocument, wherein the transaction input further includes at least onepiece of additional document information, and wherein the additionaldocument information includes a transaction ID representing informationon a location of the document-transmitting transaction function value,created by applying the specific operation to the document-transmittingtransaction, in the blockchain database, (ii) a content section, and(iii) a signature section.
 24. A document-managing server for issuing adocument based on a blockchain, comprising: a transceiver for acquiringa document-issuing request from a document issuance requester; and aprocessor configured to execute instructions to perform or supportanother device to perform processes of: (I) instructing adocument-issuing server of a document-issuing institution which has anissuance permission of the document to acquire identificationinformation on the document wherein a management permission of thedocument is given to the document-issuing institution, and instructing adocument-storing device to acquire location information representingwhere the document is generated or stored by referring to theidentification information on the document, to thereby acquireinformation on an original document including the document itself or itsprocessed one which is generated or stored as corresponding to thelocation information and (II) (i) generating contents of adocument-transmitting transaction representing a transfer of themanagement permission of the document from the document-issuinginstitution as a transmitter of the document to the document issuancerequester as a recipient of the document, and transmitting thedocument-transmitting transaction to a blockchain database, to therebyinstruct the blockchain database to store a document-transmittingtransaction function value, created by applying a specific operation tothe document-transmitting transaction, in the blockchain databaseitself, and (ii) displaying or supporting another device connected withthe document-managing server to display access information, to be usedfor accessing an issuance result of the document and the information onthe original document, to the document issuance requester, wherein thedocument-transmitting transaction includes header information, atransaction input, a transaction output, and at least one redeemingcondition-determining code configured to determine at least oneredeeming condition, wherein the transaction input includes at least oneof (i) information on personnel with a document-viewing permissionrepresenting who has the document-viewing permission of the document,(ii) a previous document-transmitting transaction function value createdby applying the specific operation to each previousdocument-transmitting transaction which is referred to by thedocument-transmitting transaction, (iii) an output index of said eachprevious document-transmitting transaction, and (iv) at least onesignature value of at least one document transmitter who transmitted thedocument, wherein the previous document-transmitting transactionfunction value included in the document-transmitting transactioncorresponding to an issuance of the document is a null function value,and wherein the signature value of said at least one documenttransmitter is a signature value of the document-issuing institution,and wherein the signature value of said at least one documenttransmitter is included in the document-transmitting transaction.